Pilot attachment



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Patented Apr. 26, 1938 UNITED STATES PATENT OFFlCE PILOT ATTACHMENT Hugh M. Albee, Orange, Mass, assignor to The Leavitt Machine Company, Orange, Mass, a corporation of Massachusetts Application December 10, 1936, Serial No. 115,239

7 Claims.

ters and pilots of various sizes and which will maintain the pilot in rigid alignment with the axis of the cutter-carrying spindle.

One of the primary features of the invention consists in providing the pilotattachment with a portion adapted to encircle the spindleof the machine to the rear of the cutter and with means for forcing the spindle encircling portion into engagement with the rear face of the cutter.

Another feature of the invention consists in providing the pilot attachmentwith a slot for receiving the cutter and with screw means engageable with the outer end of the cutter-carrying spindle for moving the attachment longitudinally of the spindle so as to abut against the rear face of the cutter.

Other features of the invention, residing in advantageous forms, combinations and relationsof parts, will hereinafter appear and be pointed out in the claims.

In the drawing, v

Figure 1 illustrates a valve seat facing machine of conventional form, which is provided with the pilot attachment forming the subject of the present invention.

Figure 2 is a vertical sectional View of the pilot attachment, the cutter and the adjacent portion of the spindle.

Figure 3 is an end view 'of the pilot attachment and cutter. I

Figure 4 is a side elevational view, taken at right angles to the view in Figure 1, illustrating the lower portion of the spindle, the cutter and the pilot attachment.

For purposes of illustrating the invention, a valve seat facing machine of the general type shown in my Patent No. 1,597,499, dated August 24, 1926, has been chosen, but it will be apparent to those skilled in the art that the pilot attachment may be used just as efiectively on valve seat facing machines of other types employing a rotatable spindle provided adjacent one end with a facing tool or cutter.

Referring more particularly to the drawing, l designates the valve facing machine as a whole and 2 the rotatable spindle thereof which is provided at one end with a screw threaded boss 3 of reduced diameter for receiving a cutter 4 which is dle until the top- Wall of the slot 8 firmly engages conventionally of substantially rectangular shape in cross section. The boss, being of smaller diameter than the adjacent portion of the spindle, provides a shoulder 5 against which the cutter is adapted to abut whenscrewed onto the boss.-

The pilot includes a member 6 which may be conveniently of substantially cylindrical shape and it is provided with a portion 1 which is adapted to encircle the spindle as a bushing at the rear of the cutter and with a transverse slot or'open- -ing 8 in which the cutter is adapted to be disposed. In order that the attachment maybe used in connection with cutters of greater" thickness and, therefore, of larger size'thanf that shown in the drawing, the distance between the; 15 upper and lower'walls of the cutter receiving slot exceeds the thickness of the cutter shown and for a purpose that will-hereinafter appear, the top wall of the slot, instead of being flat, is preferably provided with a plurality of longitudinally-1 extending ribs 9. 20

In advance of the-cutter, member 6 is'provided with a screw-threaded boss or projection It) for receiving a pilot H of suitable shape and size.

. The projection I ll is formed'with a longitudinally:

extending threaded opening in which a set screw I2 is mounted for rigidly connecting the pilot attachment to the spindle. The set screw is adapted to engage the outer end of the spindle to move the member 6 longitudinally of the'spin- 30 the rear face of the cutter. The axis of the 'set screw is coincident with that of the spindle and, while-the screw may engage and cooperate with the spindle in any desired manner, the latter is preferably provided in its outer or lower 'end with an accurately centered conical recess for receiving the conical inner end l3 with which the setscrew is also preferably formed. 4

As the portion 1 of the pilot attachment encircles the spindle as a bushing to the rear of the cutter andas the set screw l2 firmly engages the outer end of the spindle, it will be appreciated that the'pilot attachment and, therefore, the pilot is" maintained in rigid alignment with the axis 45 of the spindle. Moreover, as the set screw'forces the spindle encircling portion 1 of the attachment into engagement with the rear face of the cutter, the relative positions of the cutter and pilot in the direction of the longitudinal axisof the spindle is always definitely maintained.

In connecting the attachment to the spindle, the cutter is first inserted in the slot 8 of the attachment and it is positioned therein so that the axis of the threaded opening with which it 55 is provided for receiving the threaded boss 3 of the spindle will be in alignment with the axis of the spindle-encircling portion 1 of the attachment. The cutter is then in position to be screwed onto the boss 3 by rotating the attachment in the proper direction, the rotation being continued until the cutter abuts against the shoulder 5 of the spindle. The set screw, which previously has been backed off sufliciently to enable the cutter to have been readily inserted within slot 8 of the attachment and also sufficiently to enable the cutter to engage the shoulder 5 before the set screw engages the outer end of the spindle, is then rotated so that its inner end will be projected into the conical recess I3 in the end of the spindle. Upon being tightened so as to firmly seat within the conical recess, the set screw draws the attachment along the spin- -dle to force the spindle-encircling portion 1 H of the desired size may engaging the rear face necessity of accurately machining the entire wall. Moreover, as .the; attachment is drawn against thereof into engagement with the rear face of the cutter, which has been previously rigidly connected to the spindle, and thus effects rigid connection of the attachment to the spindle. A pilot be connected to the attachment either before or after the latter has been secured to the spindle.

By providing the'top wall of the slot 1 with longitudinally extending ribs 9, it will be apparent that a smooth bearing surface is obtained for of the cutter without the the'cutter, the cutter. serves to fix-the position of the pilot with respectthereto in the direction of the longitudinal axis of 'thespindle and as it passes through a slot in the body of the attach- "ment, it functions as a key preventing rotation of the attachment relatively thereto.

It is sometimesnecessary to lengthen the ro-v tatable spindle of valve seat facing machines by a suitable extension so as to: properly-position the cutter with respect to the valve seat to be faced and it will, of course, be appreciated and. understood that the pilot attachment may be applied as effectively and with equal facility to such an extension as to the spindle itself.

WhatIclaim is: V j

1..A pilot attachment for a valve seat facing machinehaving a rotatable spindle provided with a cutter; said attachment comprising a member having a portion adapted toen circle said spindle to the rear of said cutter, means for moving the member longitudinally of the spindle forforcing said portion into engagement with the rear face of thecutter, and a pilot carried by said member 7 in advance of the cutter.

2. A pilot attachment for a valve seat facing machine having a rotatable spindle provided with a cutter, said attachment comprising a member having a slot in which said cutter is adapted to bedisposed and also having a portion adapted to encircle said spindle to the rear of the cutter,

means .engageable' with the outer end of the spindle for forcing said portion of the member into engagement with the rear face. of the cutter,

and a pilotcarried by said member in advance of the cutter. I

3. A pilot attachment for a valve seat machine having a rotatable spindle provided with a cutter, said attachment comprising a member facing having a portion adapted to encircle said spindle to the rear of said cutter, screw means coaxial with said spindle and engageable with the outer end thereof for forcing said portion of the member into engagement with the rear face of the 'to the rear of the cutter, and also having a screw threaded boss coaxial with the spindle adapted to be disposed in advance of the cutter, screw means engageable with the outer end of the spindle for forcing the spindle encircling portion of the member into engagement with the rear face of the cutter, and a pilot removably mounted on said boss.

5. In a machine for facing valve seats, the combination with a rotatable spindle having a screw threaded end, of a cutter screwed on said end 7 of the spindle, means for connecting a pilot to the spindle including a member having a portion encircling the spindle to the rear ofrthe cutter,

screw means mounted on said member coaxial with the spindle and engageable therewith for forcing the spindle-encircling portion of said member into engagement with the rear face of the cutter, and a pilot mounted on said member in 7 advance of said cutter. c -6. In a machine for facing valve seats, the

combination with a rotatable spindle having a conical recessinone end thereof, of a-cutter mounted on the spindle adjacent its recessed end, means for connecting a pilot to the spindle including a member having a portion encircling the spindle to the rear of thecutter, screw means mounted on said member having a conical end adapted to extend into said recess in' the spindle,

said screwv means being adapted to move said member longitudinally of the spindle to force 3 the spindle-encircling portion thereof into engagement with the rear face of the cutter, and a pilot mounted on said member in advance of the cutter.

'7. In a machine for facing valve seats, the combination with a'rotatable spindle having a screw threaded boss at one end thereof, said boss providing the spindle with a shoulder, of a cutter screwed on said boss in engagement with said shoulder, means for connecting apilotto the. spindle including a member having a portion encircling the spindle to the rear of the cutterand also having a screw threaded projection disposed in advance of the cutter, a set screw'mov- I able within said projection and engageable with;

the outer end of said boss of the spindle for forcing thespindle-encircling portion of said mem her into engagement with therear face of said cutter, anda pilot screw threaded on said projection. V

HUGH M. ALBEE. 

